The purple ribbons fluttering from mailboxes, neighborhood trees and car antennas. Or maybe you've seen the signs featuring baby Kaitlyn Russell, giggling and raising her denim dress.

The ribbons and signs are pleas from Kaitlyn's mother, Tammy Russell, to never leave a child alone inside a vehicle. Last week, on the anniversary of her daughter's death, Russell drove to the site at Lake Mathews where Kaitlyn died after being left inside a sweltering van by a babysitter last year. She released balloons for Kaitlyn there and at her gravesite afterward.

"It's so sad," Russell said from her Corona home, where a large portrait of her 6-month-old daughter, who had been born prematurely, is framed on her living room wall.

Kaitlyn's babysitter at the time, Sue Calderon, has said she forgot the infant was in the vehicle when she went to pick up materials she needed for home-schooling her own three children. Temperatures inside the vehicle swelled to 130 degrees. Kaitlyn died of hyperthermia. Calderon faces child endangerment and manslaughter charges.

A desire to prevent similar deaths gives Russell the fortitude to tell her story, again and again, through tears and strained memories. After her daughter's death, Russell founded 4 R Kids Sake, a safety advocacy organization.

Tammy Russell clutches a photo of her daughter, Kaitlyn, who died last year after being left inside a babysitter's van. DAVID BAUMAN / THE PRESS-ENTERPRISE

"It's continuing," she said of the prolific number of deaths of babies and children left inside hot cars.

"I think people have the `It-won't-happen-to-me' syndrome.' "

Russell may be right.

Last year, 32 children died nationwide from heat-related incidents after being left alone inside an unattended vehicle. This year, with the exception of May, at least one child has died each month in California in incidents stemming from being left alone inside a vehicle. Two of those children were from the Inland area and one from the Coachella Valley.

"I think we have a very long way to go," said Janette Fennell, co-founder of Kids 'N Cars, a San Francisco-based safety advocacy group.

Fennell and a think tank of medical, pediatric and safety advocacy groups met this year after studying the reasons why children were left alone in vehicles.

"We found that over and over again, that people really didn't understand how dangerous a practice this is," she said. "It has no social or economic norm. . . . People don't understand the danger."

Fennell is hopeful that laws will help decrease the number of deaths.

State Sen. Jackie Speier, D-San Mateo, this year introduced "Kaitlyn's Law," which would make it illegal to leave a child age 6 or younger alone inside a vehicle where it puts the child at significant risk. The bill was passed by the Senate and awaits a vote by the Assembly.

Penalties would include a $100 fine and possible parenting classes.

Eleven states have some type of law outlawing the practice of leaving a child alone inside a vehicle. Several more have laws pending.

Tammy Russell's other two children, Derek, 5, and Kristen, 3, still ask for their little sister.

She's in heaven, and they'll see her one day, is how Russell explains Kaitlyn's absence to them.

And every day, Russell tries to find an explanation herself.

"She was our miracle baby," she said. "There's a lot of sorrow. It's still day to day."

Michael Coronado can be reached by e-mail at mcoronado@pe.com or by phone at (909) 737-1366.